水路誌記載情報の階層分類法と電子メディア化

抄録

Navigational information is divided into two categories. One is "Dynamic navigational information" and the other is "Static navigational information." The former is real-time information about ship's conditions and her environment at sea, which change every moment. The latter is stable information of hydrographic publications, which are nautical charts, sailing directions and international code of signals for examples. In order for ships' operators to get static navigational information, they try to retrieve manually the necessary information from the hydrographic publications on board. In this paper, we describe database concept of static navigational information that is presented by sailing directions. The method for electronic digitalization of Seto Inland Sea Sailing Directions is proposed in order to change their manual retrieving to automatic one on board. The first step of the method is to classify the information types of the sailing directions. The second step is to construct the hierarchy structure using the information types for the sailing directions. And, the next step is to product the database of Seto Inland Sea Sailing Directions. The database realizes safe and efficient navigation at sea in the world.